Summary of ten defects of PCB board design process

- Sep 22, 2018-

1.The definition of processing level is not clear

The single panel is designed on the TOP layer. If it is not done in a positive or negative way, it may be difficult to solder the plate with the device.

2.Large area of copper foil is too close to the outer frame

Large area of copper foil should be at least 0.2mm away from the outer frame, because when milling the shape, such as milling on copper foil easy to cause the copper foil warping and resistance solder off problems.

3. Draw the pad with filling block

The filling block is designed to pass DRC inspection in circuit design, but is not suitable for processing. Therefore, the type of welding pad cannot directly generate resistance welding data. When soldering flux is on, the filling block area will be covered by resistance soldering agent, resulting in the device welding difficulty.

4, the electric formation is also the flower welding plate and the connection

The layer is the opposite of the actual printed plate figure. All connections are isolated lines. When drawing several sets of power supplies or several types of ground isolation lines, care should be taken not to leave any gap.

5Characters are scrambled

The SMD welding strip of character cover welding pad brings inconvenience to the PCB on - break test and component welding.Character design is too small, making screen printing difficult, too large to overlap the characters, difficult to distinguish.

6The surface mount parts pad is too short

This is for the on-off test. For the over-tight surface mount device, the distance between the two legs is relatively small, and the welding pad is also very thin. The mounting of the test needle must be in an up and down staggered position.

7. Single side welding disc aperture setting

The single face pad is generally not drilled. If the hole needs to be marked, the hole diameter shall be designed to be zero.If the numerical value is designed, the hole coordinates will appear at this position when the borehole data is generated, and problems will arise.One - sided pads should be specially marked if they are drilled.

 

8.Pad overlapping

In the drilling process, the drill bit will be broken due to multiple drilling in one place, resulting in hole damage.The two holes in the multi-layer board overlap, and the film is shown as the isolation plate, resulting in scrap.

9. Too many filling blocks or filling blocks are filled with very thin lines in the design

The light painting data is lost, and the light painting data is incomplete.As the filling blocks are drawn one by one with lines in the light painting data processing, the amount of light painting data is quite large, which increases the difficulty of data processing.

10. graphics layer abuse

Some useless wires were made on some graphics layers, but more than five lines were designed on the original four layers, which caused misunderstanding.Against conventional design.The design should keep the graphics layer complete and clear.